Process of producing condensation products having tanning action



Patented Nov. 14, 1939 v 2,179,800

UNITED STATES VPATENTCTOFFICE,

PROCESS OF PRODUCING CONDENSATION PRODUCTS HAVING TANNING ACTION HermannSchuette, Mannheim, Germany, assigner to I. G. FarbenindustrieAktiengesellschaft, Frankfort-on-the-Main, Germany No Drawing.Application July 1, 1938, Serial No. 216,963. In Germany July 17, 1937 6Claims. (Cl. 260-457) The present invention relates to a process of thetanning of animal hides, white leather of producing condensationproducts having tanpleasant touch, uniform grain and excellent fastningaction from dihydroxy sulphones. ness to light. They are thereforeespecially suit- I have found that high quality condensation able forthe production of upper leathers, portproducts having tanning action canbe obtained folio and furniture leathers stable .to light and 5 in asimple manner by condensing dihydroxyfor tanning reptile hides in whichthe maindiphenylsulphones at elevated temperatures with tenance of theshade of color and the fineness glycollic acid while employingsulphonating of the markings is of special importance. They agents. maybe used with advantage together with veg- 10 Suitable initial materialsfor the said process etable tanning agents, as for example sumach 10 arefor example 4,4-dihydroxydiphenylsulphone, or gall nut extract, or alsotogether with syn- 4/l-dihydroxy 3,3 dimethyldiphenylsulphone, thetictanning agents, as for example the prod- 2,2'dihydroxydiphenylsulphone,and sulphones ucts obtainable according to the United States of the saidkind which are substituted by halogen Patents Nos. 1,414,045, 1,421,722and 2,038,529.

atoms, carboxyl, ester or amino groups, such The products obtained inthe present case infiuas 4,4'-dihydroxy-3,3'-dibromodiphenylsulphoneence very favorably the color of the leather and the like. The glycollicacid is used, for exobtained by chrome tanning.

ample, in amounts of from about to 1 The following example will furtherillustrate molecular proportions for each molecular prothe nature ofthis invention but the invention portion of the sulphone. is notrestricted to this example. The parts are 20 As sulphonating agentsthere may be menby weight. tioned for example concentrated sulphuricacid, Example oleum and chlorsulphonic acid; these may be used inamounts of from about 1 to 2 molecular proportions for each molecularproportion of the sulphone in the presence or absence of diluents,Water-binding acids, acid anhydrides or other agents favoring thesulphonation or condensation. The temperature at which the condensationis carried out is generally speaking above C. and it is preferable towork between and 160 C. Temperatures which are too 100 'parts of4,4-dihydroxydiphenylsulphone are heated to from to C. whereupon, whilestirring, there is added a heated solution of 16 parts of crystallizedglycollic acid in 40 parts of concentrated sulphuric acid. Thetemperature of the mixture is then raised to from to 0., whereby thereaction proceeds with complete liquefaction and foaming. The 30reaction mixture is kept at the said temperav ture until a samplethereof is soluble in water,

seri s: ana rams r 25 5 e 35 the initial material or on the condensationgg z g i gd to ggo l dilr t diggti 325 3 32 35 product Under the Saidworking condltlons allowed to cool completely and filtered from smallusually takes at fmm 140.130 amounts of undissolved constituents. Thefiltrate a .Strong reaction with frothtng Whlch is adjusted to the usualacidity with caustic soda 15 led to Its end by subsequent heatmg of thesolution. When importance is attached to a reaction l a G1 tanning agentfree from ash, ammonia may be 40 examp e y reac W0 10 am W1 used insteadof caustic soda solution.

dihydi'oxydiphenylsulphone with an addition of concentrated sulphuricacid at elevated tempera- A.Str0ng1y d11ut.ed aquequs Solutlon 3 thereture, preferably at temperatures of from 130 to su1t1ng,prd,uct glvesan Intense eaux 45 0 C there takes place in a surprisingly shortcoloration with l per cent aqueous ferric chloride time, simultaneouslywith the sulphonation of solutonthe dihydroxydipenylsulphone, thecondensation Instead of Y P ?7 of the sulphonic acid formed with theglycollic there may also be used acid. The initial materials arepreferably so methyldiphenylsulphone Y y- 50 measured that for eachmolecular proportion of dibromodiphenylsulphone- Tanning P oduc s 50dihydroxydiphenylsulphone there are from 1 to having similar propertiesare thus obtained.

two molecular proportions of sulphuric acid and What I claim is: from /2t0 1 molecular Proportion of ycollic 1. The process of producingcondensation prodacid. ucts having tanning action, which comprises 55The condensation products obtained yield, in causing adihydroxy-diphenylsulphone at a tem- 55 to react with glycollic acid inthe presence of a sulphonating agent.

3. The process of producing condensation products having tanning action,which comprises causing a dihydroxydiphenylsulphone at a temperaturerange of between 100 and 160 C. to react with glycollic acid in thepresence of a sulphonating agent.

4. The process of producing condensation products having tanning action,which comprises causing a dihydroxydiphenylsulphone at a temperaturerange of between 100 and 160 C. to react with glycollic acid in thepresence of concentrated sulphuric acid.

5. As a new product having tanning action obtainable by condensing adihydroxydiphenylsulphone with glycollic acid in the presence of asulphonating agent.

6. As a new product having tanning action obtainable by condensing4,4J-dihydroxydiphenylsulphone with glycollic acid in the presence of asulphonating agent.

HERMANN SCHUETTE.

